Stirring of the molten portion of a cast strand is performed in order to avoid segregations, the formation of cracks, the formation of voids, and the like, in the continuously cast product. To effect stirring of the molten portion of the strand, it is known to use a so-called round stirrer of motor stator type or a straight stirrer comprising one or more partial stirrers surrounding the cast strand (see, e.g., U.S. Pat. No. 4,183,395). A disadvantage of these types of stirrers is that they are fixedly mounted around the cast strand and therefore difficult to rapidly move in the case of an operational disturbance in the form of, for example, loss of water and breakthrough in the strand.